IT Glossary
Federated identity lets one identity access systems across domains. Learn how identity federation works, federation vs SSO, and where it fits in IAM.
July 3, 2026
Federated identity is an arrangement that lets a user rely on a single digital identity to access systems across multiple independent organizations or domains. Through a trust relationship between identity providers and service providers, the user authenticates once with their home IdP and gains access to federated services without creating separate accounts. Federation is what makes cross-domain single sign-on possible.
These overlap but are not identical. Federated identity and SSO overlap but are not identical. Federated identity works across separate organizations and domains, rests on trust between distinct parties, and is what enables cross-domain SSO. SSO usually operates within a single organization, relies on one IdP across internal apps, and is a capability that federation can deliver.
A company lets employees access a partner's portal using their own corporate login, because the two organizations federated their identity systems. No partner account is created or managed. Federation reduces credential sprawl across business relationships, but each federated trust is also an access path that governance has to track, especially when partnerships end.
SSO usually means one login across an organization's apps. Federated identity extends that trust across separate organizations or domains, which enables cross-domain SSO.
Mainly SAML and OpenID Connect, which let an IdP issue assertions that a service provider in another domain can trust.
Each federated trust is a live access path. If it is not tracked and revoked when a partnership ends, it can leave unintended access open.
